Announcing A New Belted extremely compact Extruder - The Nova Pro

I’ve been working on this as a side project off and on for a little while now. I’ve always been interested in belt driven extruders, because they theoretically have more responsive retraction than a geared design. I also wanted something that had as absolutly as short a distance between the hobbed things to the hotend as possible, used a Bondtech dual drive hob core, had an easy to access idler. and was stiffer on the mount than other designs. And thus, this extruder was born.

Presenting, the Alpha revision of the Nova Pro Belted Precision Extruder! (lots of pictures, files further down along with more details)

Project repository:

Here are the build files:

There will eventually be a left hand and a right hand variant of this extruder body, to allow for a more compact dual extruder. There is also going to be a lower fan shroud. For now you can use the stock E3D V6 fan. Also this presently fits an E3DV6 and requires a circular 6mm thick Mounting flange, several M3 bolts, an 8mm bondtech extruder core (roughly $85 shipped in from Sweden), belts, pulleys and M3 bolts. Also an M8 bolt and some washers. A full parts list, sources, etc. will be posted once its finished.
NovaPro_Taz_mount_rh_1_0_a.stl (712 KB)
NovaPro_Tensioner_2_1_a.stl (43.1 KB)
NovaPro_Idler_Latch_1_2_a.stl (184 KB)
NovaPro_Extruder_Body_RH_1_0_a.stl (585 KB)
NovaPro_Idler_Half_1_RH_1_0_a.stl (59.8 KB)
NovaPro_Idler_Half_2_RH_1_0_a.stl (73.3 KB)

More pictures:

This extruder is officially hereby licensed under Creative Commons - Atribution. Other format files are available upon request, I just don’t like generating them if no one is going to use them.

I noticed that there is a bigger diameter section just below the hobbed gears. Do you plan to insert a short piece of PTFE tube there?
How do you change the filament with this system, is it necessary to unscrew the two screws completely?

The lower filament hole should be the same diameter as the upper at the moment. I’ve debated putting the PTFE in there, it’s a short enough run I don’t know that it would do anything positive to the feed path though. I can certainly make a variant that allows for it.

To load filament, you just slide the latch up, flip the idler down, and then remove the old filament. if there is no filament loaded already, you cana ctually just load it by sticking the fiillament in from the top and hitting advance on the extruder too.

Lower duct parts now exist. also more pictures:


I’m not sure I’m 100% done with the outer fan ducts yet, but the center turned out great. The new mount plate is required to fit the ducting, though if you already printed the old one you can just cut the ends off of it, as that is the only change. I’ll also be making a large pile of “nameplate” ID tags for the extruder body in the next few days to tell multiple extruders apart. Examples “E3Dv6 0.5mm” or “extruder 1, 2, 3” or “Extruder A, B, C” etc. If you have a naming scheme you like to use, please let me know what it is and i’ll make sure to add it.
NovaPro_RL_Duct_2_7_c.stl (661 KB)
NovaPro_Taz_mount_rh_1_1_a.stl (697 KB)
Novapro_ID_E3Dv6_5.stl (458 KB)
NovaPro_Center_Duct_back_1_0_a.stl (468 KB)
Novapro_ID_Blank.stl (16.8 KB)
NovaPro_Center_Duct_1_0_a.stl (441 KB)

Have you tested flexible materials through it yet? It would seem this would work well with either rigid or the most flexible filaments.

It seems to feed great so far. I haven’t finished wiring the hotend yet to test it further than that. but in terms of constraint path and travel distance, it should feed even better than my dedicated flexible filament model. The only difference is this one lacks the PTFE tube, but for such a short distance I don’t think it will even be noticed as missing.

I finally had a chance to get back on this project. Here is revision 2.0 of the main extruder body. I’ll need to adjust the mount to fit the changes I made as well, so this will not fit the 1.0 mount, it will leave a gap. Look for the new mount to go with it tomorrow, along with a few for several other printers.

This latest version eliminates the 608zz bearings and replaces them with two smaller ones, a 12mm dia unit in the front, and a 15mm dia unit at the rear. That allows me to make the entire extruder 2mm thinner, eliminate about 1/8th the plastic around the bearing housing itself, use a shorter bolt, and cut the bearing weight down to 1/2 of 1 608zz bearing down from 2 of them. I may still be able to get a bit more plastic weight down by making the upper segment shorter, but the upper mount point has to be above the rear pulley so there is very little material I can remove there anyways.

I’m pretty happy with how it looks, we’ll see if it prints as well. if it does and everything lines up, this will probably be the variant I issue the left hand version of for use with dual extruder setups
NovaPro_Extruder_Body_RH_2_0_a.stl (473 KB)

Ended up shringing it down a bit more
NovaPro_Extruder_Body_RH_2_1_a.stl (489 KB)
NovaPro_Taz_mount_rh_2_0_a.stl (662 KB)
NovaPro_Idler_Half_2_RH_2_0_a.stl (74.3 KB)
NovaPro_Idler_Half_1_RH_2_0_a.stl (59.4 KB)

Here’s the Nova pro Mk 2 roughly mocked up. The new side fans ended up being too long so I need to redo them, and there is at least one more area of clearance I need to add to the final release model where the two internal gear sets mesh, but i’m pretty happy with it now. I do think there is something I haven’t thought of yet to shrink the upper portion of the latch mechanism down a bit, and the front center fan may be able to be moved back another 2-3mm but other than that things are lining up about as efficiently as possible, and the new center core with the small front bearing and the smaller than 608zz but slightly larger than the front rear bearing are both working great. I literally took it for a spin and told a donar motor to spin it around a few thousand times, no binding, no debris or powder, etc.

Anyways, here it is:

The main change aside from the massivly reduced center spindle bearing arrangement is that this version is around 4mm thinner overall, has a mor compact idler, uses a much shorter center 8mm bolt (which reduces weight) and adds a second mounting lug for the side fans to lock them in position. That adds a tiny bit of weight but it is a fraction of the amount I removed with the other changes. There will be a 2.2c variant of the body that has a clearance notch for the gear mesh, but otherwise you can consider this a final revision for now. Overall it’s about 1/5th lighter than it was.
NovaPro_Extruder_Body_RH_2_2_b.stl (472 KB)
NovaPro_ID_055_1_0_a.stl (497 KB)
NovaPro_belt_guard_1_0_a.stl (36.7 KB)
NovaPro_RL_Duct_3_7_c.stl (744 KB)

So how does it print?

Not sure yet. Version 1 prints great, crisper than my already good e3d variant wade setup in small details. Version 2 has not been tested yet because I haven’t been home long enough to finish it up. Last weekend was off site projects, this weekend was replacement car sourcing since I broke my old one. I should get it finished this week though, I do know the new fans seem to have plenty of flow, and the motion segment is smooth with zero slop. I also have a new motor on the way I want to fit.

Looks pretty awesome. Do you have a BOM for everything we’d need to build this, by chance?

Yes, I’ll post it when I get home tonight. The hard to source bits are the two bearings, the 8mm Spacer washers from openbuilds, , the bondtech 3.00mm core kit, the belt and pulleys from sdp-sI. Everything else is m3 bolts, heat set inserts and fans.

Here’s one with all the hard to find stuff. The easy to find things like M3 bolts, I need to measure, that will happen when i tear it down to document the assembly process. This will get cleaned up further as well. but for now aside from the M3 bolts this will get you close. I am considering going with a smaller motor pulley as well. it would save weight and increase torque, and I have room to go with a smaller one with the existing slider. I haven’t decidede which one to bring in yet though
1 Bondtech Drive gear kit for 3.00mm fillament $50 - (Closer to $80 with international shipping)
1 128-2Z 8mm shaft 12mm OD 3.5mm wide Stainless Steel bearing -Mcmaster Carr part 7804K115 $7.21
1 688-2Z 8 16 5 Stainless Steel bearing -Mcmaster Carr part 7804K117 $6.13
1 Gates 2MR88 belt SDP/SI part number A_6R51M088060 $4.82
1 2mm GT2 65 tooth pulley with brass insert for 8mm bore Polycarbonate for 6mm wide belt SDP Part number A 6Z51M065DF0608 $8.69
1 2mm GT2,36 Tooth pulley with brass insert for 5mm Bore Polycarbonate for 6mm wide belt SDP Part number A 6Z51M036DF0605 $6.33
2x 8mm shim $0.25 ea Openbuilds
1 8mm dia Stainless Cap head bolt 50mm long - Locally sourced (or whatever 8mm bolt you want to use here)
2x 20mm long M3 bolts for idler
2x 18mm long M3 bolts to hold the lower fan mount on
a dozen M3 heat set inserts, half a dozen assorted as yet uncatalouged M3 bolts frm 6mm long to 12mm long shafts, 2x 24v 40mm fans, 1x 5v 30mm fan, an E3Dv6,
6 M3 nuts (2 for idler arm 4 for hotend mount )
2x idler arm springs from a wade style extruder (not sure what part number for these, I just used ones off an existing extruder
4x M3 washers
1x This or similar Ring E3Dv6 mount $3.68
wire ends and fittings for your particular 3d printer setup
small zip ties
half height NEMA 17 motor
1/4lb ABS plastic

Edit: going to try this pulley too. I need to find a 24 tooth one somewhere easy to source. that would probably be ideal.

You new extruder has to be realy awsome - it looks like they gave it a try at e3d and they thought it’s worth to redesign the Titan extruder :laughing:

The funny thing is that my fillament path is still technically shorter. Though I may see if I can make the whole thing even shorter with one of those plate heat sinks.

Nice!! I’ve been away from the forum for far too long.